Study examines role of ghrelin receptor in fat tissue inflammation and insulin resistance

August 23, 2016 by Paul Schattenberg

Scientists have proposed that inflammation is the harbinger of aging and central to the aging process, a phenomenon described as ‘inflamm-aging,’ said Dr. Yuxiang Sun.

Sun, a faculty member in the department of nutrition and food science at Texas A&M University in College Station, said aging is commonly associated with low‐grade adipose inflammation, which is closely linked to insulin resistance, a condition often leading to type 2 diabetes.

In research recently published in the premier science journal Aging, Sun and colleagues investigated the role of the ghrelin receptor, growth hormone secretagogue receptor, or GHS‐R, in age‐associated adipose tissue inflammation and insulin resistance in mice.

“Ghrelin is a ligand, a molecule that binds to a specific receptor to transduce specific kind of signal” she explained. “GHS-R is the receptor of ghrelin, for which it has a binding pocket for ghrelin. Ghrelin and GHS-R work like a key and a lock.”

She said hunger stimulates the ghrelin section in the gut, which activates brain regions where GHS-R is highly expressed, triggering the hunger sensation. Ghrelin enhances appetite and increases weight gain, promoting obesity and insulin resistance.

“To date, ghrelin is the only known orexigenic or appetite-stimulating hormone,” she said. “The pharmaceutical industry has been calling ghrelin ‘the key to obesity’ since its discovery. We investigated the impact of ghrelin signaling on adipose tissue macrophages, in order to understand the role of ghrelin signaling in obesity.”

Sun said obesity, in essence, is a low-grade chronic inflammation in adipose tissues. Adipose tissue serves as a major endocrine organ, secreting various hormones and cytokines which play crucial roles in normal metabolism and obesity-associated dysfunctions.

Continue reading the rest of the article and quoted study at the links below.